Silicon wafer chips are brittle and easily damaged in handling. In addition, chips are also easily contaminated by dust or dirt particles and moisture.
The present invention, generally, provides a protective container for silicon wafers that supports the wafers with minimal contact and protects the wafers from contaminants.
More particularly, the present invention provides a container that supports at least one wafer in a horizontal orientation by edge portions of the wafer. The container of the present invention also provides lateral and vertical constraints to prevent movement of the wafer within the container.
The present invention also provides a sealable container to protect at least one silicon wafer in the container from moisture and particle contamination.
According to the present invention, a container comprises a body having a bed and a side wall defining an interior space. A plurality of upright posts are formed in the bed in the interior space and define a perimeter for at least one containing area for a wafer. The posts maintain a lateral position of a wafer chip in the container. The bed of the body is V-shaped within each containing area, so that portions of the bed adjacent and within two opposite sides of the perimeter provide shoulders for supporting an edge portion of a wafer chip.
The cap has a top wall and a side wall. According to an aspect of the invention, a plurality of fingers are formed on the interior side and extend from the top wall of the cap for maintaining a vertical position of a wafer chip in the container. The fingers are preferably formed with a curvature so that in a closed position a relatively broad convex side of each finger contacts a wafer chip in the container and to provide flexibility in a direction perpendicular to the top wall of the cap.
The container according to the present invention provides for a minimal contact at edge portions of the chip. The chip is supported by a portion of the bed adjacent to the upright posts and is constrained from horizontal, or lateral, movement by the upright posts. The fingers in the cap contact the chip near the edges of the chip and constrain the chip from vertical movement.
According to another aspect of the invention, a hinge connects the body with the cap, the hinge being bendable so that the cap is movable from a closed position seated on the body to an open position not seated on the body. The hinge preferably includes a groove extending in a direction transverse to a longitudinal direction of the hinge, the groove providing a weakened zone for concentrating bending of the hinge at a location to reliably and correctly position the cap relative to the body when the cap is moved to the closed position. The hinge preferably also includes a spine adjacent to the groove and extending in a direction transverse to a longitudinal direction of the hinge.
According to yet another aspect of the invention, a pair of recesses are formed in the bed in conjunction with each of the containing areas of the bed to provide access to the edges of the wafer for removing the wafer from the container. Preferably, the recesses are formed at opposite sides of each containing area.
The body further includes a plurality of radially arranged reinforcing ribs formed on an exterior side of the bed of the body to stiffen the bottom to provide protection for the wafer.
A further aspect of the invention includes means for sealing the cap to the body that is air and water tight when the cap is in the closed position. The means for sealing the cap preferably comprises an annular projection formed on an interior side of the top wall and spaced from the side wall to form an annular channel for receiving an end of the body side wall. According to a preferred embodiment, the end of the body side wall is shaped with an outwardly directed rim and the side wall of the cap is shaped with an inwardly directed circumferential ridge spaced from the top wall, the side wall between the ridge and the top wall and the annular projection forming the annular channel.
According to another aspect of the invention, the sealing means further includes a flange extending outwardly from the side wall of the body and a flange extending outwardly from the cap, the body flange and the cap flange contacting when the cap is in the closed position.
According to a further aspect of the invention, the container includes a destructible member integrally attached to one of cap and the body and attachable to the other of the cap and body when the cap is in a closed position, wherein the cap can be opened only upon destruction of the destructible member.
According to yet another aspect of the invention, the side wall of the container extends beyond the bottom of the bed to provide a free edge, and a top, outer surface of the cap is formed with a projection providing a shoulder to receive the edge of another container, so that two or more containers according to the present invention are vertically stackable.